1. Field of the Invention
The present invention relates to an anode containing silicon (Si) as an element and a battery using it.
2. Description of the Related Art
In recent years, as mobile devices have been sophisticated and multi-functionalized, a higher capacity of secondary batteries as a power source for these mobile devices has been demanded. As a secondary battery to meet such a demand, there is a lithium ion secondary battery. However, since graphite is used for the anode in the lithium ion secondary battery in practical use currently, the battery capacity thereof is in a saturated state and thus it is difficult to attain a significant high capacity thereof. Therefore, it is considered to use silicon or the like for the anode. Recently, forming an anode active material layer on an anode current collector by vapor-phase deposition method or the like has been reported (for example, refer to Japanese Unexamined Patent Application Publication Nos. H08-50922 and H11-135115, and Japanese Patent Publication No. 2948205). Silicon or the like is largely expanded and shrunk due to charge and discharge, and thus there has been a disadvantage that the cycle characteristics are lowered due to pulverization. However, when using the vapor-phase deposition method or the like, such pulverization can be prevented, and the anode current collector and the anode active material layer can be integrated. In the result, electron conductivity in the anode becomes extremely favorable, and high performance both in the capacity and the cycle life is expected.